Surgical saw



June 15,1926. y 1,588,531

H. DENNIS v SURGICAL SAW Fil-ed March l, 1924 Patented June 15, 1926.

UNITED STATES PATENT OFFICE.-

OF AMERICA, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

SURGICAL SAW.

Application filed March 1, 1924. SerialvNo. 696,145.

My invention relates tov an improvement in surgical saws of the rotary motor operated type and its novelty consists in the adaptation and arrangement of parts as will be more fully hereinafter pointed out.

There has been greatdiiiiculty in making 'deep incisions in bone operations as most of the devices available are not adapted for that purpose. My device not only is capable of making any necessary incision but at the same time has furnished a device adapted to be used for drilling operations which are often necessary in bone operating so that the interchangeability of the device is important in saving valuable time in the course of such operations. n, v

My device also is readily sterilized and meets all yof the requirements essential to successful bone operations.

Referring to the drawings Figure 1 is a perspective of my complete device without the power connections. Figure 2 is a side view of the arm carrying the transmission of the saw and is broken away at the shaft end to show the interior mechanism. `Fig ure 3 is a vertical section of the outer .end of the shellV and shaft connecting up with the motor. Figure 4 shows one type jot single saw mounted in position for use, the

rest of the Varm being broken away for convenience in illustration. Figure 5 shows another type of single saw mounted in position for use with the arm broken away as in Figure 4. Figure 6 is a side view of twin saws with parts of the saws and connections being broken away as in Figure 4. Figure 7Y is a plan View of the shaft, the inside end being broken away for convenience in illustration.

In the drawings shell members 8 and 10 are locked together at 9 and contain an electric motor of the usual type used in instruments of this class. in the head ot the shell 10 is a connecting member 11,-being internally threaded at 13, whereby it is adapted to be secured to the motor which is not shown herein. The outer end of said connecting member 1l is also internally threaded at 45 so as to receive a bea-ring member 12 which is externally threaded so as to engage the internal threading 45 of 1l. A lock nut 46 is adapted to be threaded over 45 so as to lock shell 10, connecting member 11 and bearing member 12 together. The connecting memberll has a dividing wall 14 having a central opening 15. Spacing member 16 having a cutout portion 17 is adapted to receive one race of ball bearing 18 and a second cutout portion`19 in the dividing plate 15 is adapted to' receive the other race of said ball bearing 18. -A cylindrical shaft 20 is adapted to be mounted inthe bearing member 12 and it has a reduced inner cy- `][T.l'(`ar. DENNIS, OF NEV YORK, N. Y., ASSIGNOR TO THE KNY-SCHEERER CORPORATION lindrical end 21 one-half of which is cut plates secured together and having a collar 25 is adapted to be mounted on the bearing member 12 by means of set screw 26. The arm 24 also' has a movable gear shifting member 27 pivoted at 28 and carrying a gear 29 on a pinion 30. The shifting member 27 is secured in position by means of a thumb screwl31 and as this is released the carrying member 27 may be dropped into the lower position as shown in dotted outline in Figure 2, thereby loweringthe gear 29 from mesh with gear 23. A geark 32 is mounted lon the pivot or trunnion 28 and a series of gears the same as 32 are similarly mounted on trunnions the length ot the arm 24 so that thegear at the outer end of said j arm 24 mountedon shaft 33 will drive said shaft 33 whenever the gear 29 is in position to mesh driving gear 23 and driven 'gears 32 and the chain of gears inside arm 24 in mesh with said gear 32. 'A saw 34 is adapted to be rigidly secured to the shaft 33, which is threaded, by means of circular nut members 35 which are adapted to be screwed up tightly on either side of said saw 34. The shaft 33 is adapted'to be mounted at one end in the plate 43v and at the otherV end is adapted to be mounted in a bearing in an oft'- set member 36, which is adapted to be rigidly secured to the plate 44 at 37. The particular form of 36 will vary according to the particular saw to be used as is shown in Figures 4, 5 and 6. In Figure 6 the saws are twin saws 38 and 39 and are mounted in a similar manner as saws 34, on the shaft 33.

In Figure 5 the saw 4() is a larger single .saw and is mounted on the shaft 33 in the same way as saw 34.

In operating my device the gear 29 will be secured in position as shown in Figure l in mesh with thegear 23and as thepower is turned on the shaft 20 and gear 29 will bek driven thereby and vtheir motion will be transmit-ted togear 29, thence to gear 32 and to the chain of`gears in arm 24vto the shaft 33. whereby the saw 34 will be rotated. VThe particular saw desired may be secured in po- -sition before this is done as the operator will know what type of'saw will be needed for the operation. Ifpdurin'g theroperation it becomes necessary to do some drilling the power having been shut off the thumb screw 3l will be released and the gear 29 will be ,dropped down `outof engagement with gear "ing the use of the drill the arm 24 will serve a handle for the operator thereby facilitating his work and making the same more accurate. Y

The arm 24 may be removed at any time by first throwing the Ygear 29 out of engagement with gears 23 and 32 and releasing the thumb screw 26 whereupon the arm 24 can be slipped over the bearing member 12 lso that the device may be used for boring or similar purposes free from the arm 24.

It is thus seen that my device is so con-V structed that during the operation the operator can quickly and readily turn from the Y use of the sawto the use'of the drill and back again to the use of the saw without changing instrumentsv whereby a material amount of fime may be saved in the operation and the operators attention be centered upon the one device and the patient.V

I claim: y Y

1.V In a surgical s'aw the combination of an electric motor, a detachable shaft. adapted to lock into the shaft of said motor and having means for mounting vtools therein, a gear cut into said detachable shaft, a bearing member mounted on said shaft, an arm mounted on said bearing member and carrying a saw and a train ofV transmission gearsl adaptedv to transmit the motion from said shaft to said saw, a shift gear mounted in said arm and `adapted to transmit Vmotion from said gear on the shaftto said train of gears in the arm when in meshed position. Y l 2. In a surgical saw the combination of an electric motor, a detachable shaft` adapted yto lock into the shaft of lsaid motor and having means for mounting tools therein, means comprising a train of gears for transferring the motion of said shafts to a rotarysaw, and means for interrupting said transfer of motion to said train of gears. Y

3. In a surgical saw the combination of an electric motor, a detachable shaft adapted to lock into the shaft of said motor and having means for mounting tools therein, means for transferring the motion of said mot-or to a rotary saw, and means for interrupting said transfer of motion comprising an intermediate gear adapted to ymesh with a gear on said detachable shaft with a train of gears transmittingl said motion to said. saw and means for throwing said intermediate'gear out of mesh. Y 7

4. In a surgical saw the combination of an electric motor, a detachable shaft adapted to lock into the shaft of said motor and having means for mounting tools therein, means for transferring the motion of said motor to a rotary saw, and means for interrupting said transfer of motion Acomprising an intermediate gear adapted to meshV with la gear on said detachable shaft with a train of gears transmitting said motion to said saw and means for throwing said intermediate gear out of mesh embodying a pivoted support .member on which said intermediate gear is mounted.

k5. The combination with a motor and its shaft. of a separable shaft 'having' a tool l holder at its outer rend adapted to lock with said motor shaft and carrying a gear cut 100 therein, a bearing kmember mounted over said separable shaft, an arm adapted to be rigidly secured to said bearing member, a rotary saw mounted on a plate 'inthe outer end of said arm, a train of gears mounted 105 in said arm on trunnions the outer one'vbeing geared to said sawl and a gear pinioned to a pivoted shift'member in said arm so that it can manually be thrown into or out of mesh with said shaft gear and said train 110 of gears.

HUGH DENNIS. 

